Ground levelling trimmer

ABSTRACT

A ground surface trimmer  10  has a bin  14  having an open front  22  and a scraper  20  extends across the front edge of the bottom  24  so as to scrape the ground surface and collect material through the front opening into the bin  14 . A main frame  12  has a towing hitch  13  for coupling to a tractor. Two rear wheels  31  are mounted behind the bin  14  and a ram  39  is used to adjust the height of the bin and scraper relative to the wheels. A first control  26  comprising a front closure  27  is operative to selectively control collection into the bin  14  through the front opening  22  of material scraped from the ground surface and the second control  40  comprising a movable pusher  43  within the bin is operative to selectively control the discharge from the bin  14  through the front opening  22  of material within the bin  14.

FIELD OF THE INVENTION

[0001] This invention relates to trimmers which are used to level the surface of ground by grading or scraping the ground and if required spread the scraped material.

BACKGROUND OF THE INVENTION

[0002] Ground levelling machinery has been in use for years. Typically, ground levelling machinery includes massive vehicles such as road plants that are used in large open spaces such as for road making. A conventional ground levelling machine generally has only one blade. Most conventional ground levelling devices have the blade inclined to the direction of travel for directing the flow of graded material off the ends of the blade.

[0003] Conventional ground levelling devices allow the ground surface to be graded. However conventional ground levelling devices are not designed for or are not well adapted for skimming a ground surface for removing irregularities in the ground surface level.

[0004] It is also known to directly mount or to hitch mount a scraper blade behind a towing tractor. In the case of both such configurations, the scraper blade is normally canted to one side so that scraped soil is directed across the blade and discharged therefrom at the trailing side of the blade. These scrapers do not have capabilities for containing the soil and transporting it to another location.

[0005] In the construction industry in particular it would be beneficial to have a lightweight manoeuvrable final trimmer of the ground that will not damage plumbing piping or the like within the ground, which allows easy steering and will not leave substantial imprints or side furrows requiring further manual treatment of the ground. It is also desirable to have a levelling device that can level the ground surface to within relatively small tolerances.

[0006] It is therefore an object of the present invention to provide a ground levelling trimmer which overcomes or ameliorates one or more of the above identified disadvantages of known grading apparatuses, or which is effective for use in relatively small scale ground finishing operations.

[0007] A preferable object is to provide a ground levelling trimmer which can be useable in confined spaces and can be relatively inexpensive compared to the very large road plants or the like.

SUMMARY OF THE INVENTION

[0008] In accordance with the present invention, there is provided a ground levelling trimmer including a bin which includes a front opening and an associated scraper, which, in use, is able to scrape the ground surface being trimmed when the ground levelling trimmer is moved in a forward direction such that material removed by the scraper from the ground surface is collected through the front opening into the bin; a mounting means having a wheel system including at least one ground engaging wheel and a frame by which the bin is mounted, the frame being mounted by the wheel system so as to allow selective elevational adjustment of the frame and of the bin mounted thereby relative to the wheel system so as to thereby enable selective adjustment of the height of the scraper relative to the ground surface; and a material holding control associated with the bin for selectively controlling at least one of the collection into the bin through the front opening of material scraped from the ground surface and the discharge from the bin through the front opening of material within the bin.

[0009] Preferably the material holding control is operative to selectively control both the collection into the bin through the front opening of material scraped from the ground surface and the discharge from the bin through the front opening of material within the bin.

[0010] In the preferred embodiment, the material holding control includes a selectively operable closure associated with the front opening of the bin, the closure being selectively movable between a closed position in which it substantially closes the front opening against collection of material scraped from the ground through the front opening into the bin and a range of open positions which provide differing proportions of the area of the front opening to be available for passage of material scraped from the ground surface through the front opening and into the bin.

[0011] Also, preferably the material holding control includes a material pusher located within the bin and which is selectively operable to push material within the bin forwardly so as to discharge material through the front opening of the bin. The material pusher is preferably mounted in a rear of the bin, and is selectively controllable to swing forwards within the bin so as to push material in the bin forwardly towards the front opening. The material pusher may be pivotally mounted at an internal upper portion of the bin so as to be movable in an arc to push material held in the bin towards the front opening. The material pusher in vertical section may have two planar parts angled obtusely internally of the bin so that the pusher is movable forwardly from a rear retracted position which minimally encroaches on the volume within the bin and so that the bottom edge transcribes the arc when moving forwardly through the bin. The internal bottom of the bin may be arcuate in side view so that the bottom edge of the pusher follows this arcuate shape closely so as to allow effective movement of the majority of material in the bin by the pivotal forward movement of the pusher.

[0012] The trimmer may include a rearward extending frame mounted externally of the rear of the bin. A hydraulic ram may be connected between the external rearward frame and the pusher to provide the required movement of the pusher within the bin. In this configuration the ram preferably extends into the bin in order to move the pusher and material in the bin towards the forward facing opening.

[0013] The bin may have a shaped bottom having a front edge at which the scraper is located. The scraper may have a leading cutting edge defined by a leading face angled at about 45 degrees to a lower external bottom face which engages the ground surface so that an effective scraping or trimming occurs.

[0014] A transverse roller may be provided behind the ground engaging wheels for rolling along and thereby compressing the ground that has been scraped and levelled by the trimmer and for providing lateral stabilising of the trimmer during use. Preferably the roller can be selectively moved from a ground engaging position to an elevated non-ground engaging position.

[0015] The wheel system may include two spaced ground engaging wheels, which are within the lateral dimensions of the bin. Preferably the entire the mounting means including the wheel system and frame do not extend laterally beyond the sides of the bin. Preferably the scraper extends the entire width of the bin.

[0016] The mounting means may include a ram operative between the wheel system and a portion of the frame to enable selective height adjustment of the bin and associated scraper.

[0017] In a preferred embodiment the selectively operable closure comprises a front door which has a generally planar face which lies in the general plane of front opening and is selectively movable generally in that plane towards and away from the scraper to close and open the front opening. The front door may be mounted for pivoting movement about a pivot axis located inwardly of the bin behind the front opening. A front door ram may be operable between the frame of the trimmer and a link assembly coupled to the front door so as to selectively close and open the front opening.

[0018] The trimmer may include a laser receiver mounted to the trimmer to receive signals relating to the local ground level so as to thereby enable at least one of automatic height adjustment of the scraper and automatic control of the material holding control.

[0019] Ground engaging skis may be provided on opposing sides of the trimmer, and having substantially co-extensive lower planar surfaces, such that the skis help stabilize the travel of the trimmer along the ground and protect the front lower corners of the bin.

[0020] The preferred embodiment of the trimmer is towable behind a vehicle in use, the frame having a forwardly extending portion providing a coupling hitch for releasably coupling the trimmer to the vehicle and by which the front of the trimmer is supported above the ground.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Possible and preferred features of the present invention will now be described with particular reference to the accompanying drawings. However it is to be understood that the features illustrated in and described with reference to the drawings are not to be construed as limiting on the scope of the invention. In the drawings:

[0022]FIG. 1 is a diagrammatic side view of a trimmer in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] The trimmer 10 has a carrier or bin 14 having an open front 22, rear 23, bottom 24 and top 25. A scraper 20 extends across the front edge of the bottom 24 so as to scrape the ground surface and collect material through the front opening into the bin 14. The sides of the bin 14 are substantially perpendicular to provide a constant width throughout the height of the bin. The bin 14 is mounted by a main frame 12. A centre bar 15 of the frame 12 extends forwardly and has a towing connection or hitch 13 for coupling to a readily manoeuvrable tractor (not shown). The centre bar 15 extends forwards from a front cross frame member 17 from the ends of which extend rearwardly two spaced parallel side frame members 11 between which the bin 14 is located and mounted.

[0024] A rear wheel system 16 includes two rear wheels 31 mounted behind the bin 14. The wheels 31 are mounted on opposite ends of axle 32 which is mounted by a wheel frame 30 having two laterally spaced arms 33 extending rearwardly from respective pivot connections 34 provided at bottom rear corners of the bin 14. Beyond the axle 32 at the rear ends of the arms 33 is a roller support frame 36 pivotally connected at 37 to the arms 33 and mounting roller(s) 35 which are shown raised but which can be selectively lowered about pivot 37 by any suitable means to roll across the ground behind the trimmer 10 as it is advanced across the ground.

[0025] The roller 35 when travelling over the ground behind the trimmer and behind the wheels 31 compresses the ground that has been scraped and levelled by the trimmer and also provides some lateral stabilising of the trimmer as it travels forwardly. The roller 35 does not need to be locked or positively urged into its rolling position but can pivot freely about pivot connection 37 to travel over remaining irregularities in the ground surface.

[0026] The trimmer 10 includes a material holding control 26, 40 comprising two operative systems, the first of which 26 is operative to selectively control collection into the bin 14 through the front opening 22 of material scraped from the ground surface and the second of which 40 is operative to selectively control the discharge from the bin 14 through the front opening 22 of material within the bin 14.

[0027] The operative system 26 includes a selectively operable closure 27 associated with the front opening 22 of the bin, the closure 27 being movable between the illustrated closed position in which it substantially closes the front opening against collection of materials scraped from the ground surface through the front opening and into the bin 14. In the drawing, the closure 27 comprises a front door which has a generally planar face which lies in the general plane of the front opening 22 and is selectively movable generally in that plane towards and away from the scraper 20 to close and open the front opening. The front door 27 is mounted for pivoting movement about pivot axis 28 which is located inwardly of the bin 14 behind the front opening 22 whereby the door 27 lifts approximately within its own plane away from the scraper. The closure in the illustrated embodiment also has an upper closure face 29 angled inwardly and upwardly relative to the door 27.

[0028] The second part 40 of the material holding control comprises a material pusher 43 located within the bin 14 and which is selectively operable to push material within the bin forwardly so as to discharge material through the front opening 22. The pusher 43 is mounted so as to be movable from a rear retracted position as illustrated adjacent the rear 23 of the bin and is selectively controllable to swing forwards within the bin so as to push material forwardly. The pusher 43 is pivotally mounted at an internal pivot axis 44 so as to be movable in an arc. The pusher 43 in vertical section has two planar parts 45, 46 angled obtusely internally of the bin 14 so that, when moving forwardly from the rear retracted position illustrated in which it minimally encroaches on the volume within the bin, the bottom edge 47 moves along the arc when moving forwardly through the bin. The internal bottom 48 the bin is arcuate in side view so that the bottom edge 47 of the pusher 43 follows this arcuate shape closely so as to allow effective movement of the majority of material in the bin by the pivotal forward movement of the pusher 43.

[0029] A rearward extending frame 18 is mounted externally of the rear 23 the bin 14. The frame 18 includes a pair of laterally spaced V-shaped arms 41. A hydraulic ram 42 is connected between the external rearward frame 18, adjacent the vertex of the arms 41, and the pusher 43 to provide the required movement of the pusher within the bin 14. The ram 42 extends into the bin in order to move the pusher and material in the bin towards the forward facing opening 22.

[0030] The bottom 24 of the bin slopes downwardly and forwardly to provide a front edge at which the scraper 20 is located. The scraper 20 has a leading cutting edge defined by a leading face 21 angled at about 45 degrees to a bottom face of the bottom 24 which engages the ground surface whereby an effective scraping or trimming of the ground occurs as the trimmer is advanced. The leading face 21 provides a ramp up which material scraped from the ground surface travels when the closure 27 is at least partially open so that the material enters the bin 14. If the trimmer is travelling over ground at a lower level than required so that the scraper 20 is at least momentarily passing above the ground surface, material within the bin can be progressively pushed by the pusher 43 out of the bin and falls down the face 21 provided the closure 27 is at least partially open. If the trimmer is travelling over ground which is substantially at the desired level but there are minor irregularities in the ground surface, the closure 26 can be closed so that material scraped from local high spots can be pushed ahead of the scraper face 21 and ahead of the closed front door 27 to fill minor local depressions.

[0031] The wheel system 30 preferably has the two spaced ground engaging wheels 31 located within the lateral dimensions of the bin 14. Likewise components of the frame, with the exception of the side frame members 11, can preferably all be substantially within the lateral dimensions of the bin 14. The roller 35 can likewise be substantially equal to or at most slightly larger than the maximum lateral width of the bin 14. With these dimensional or criteria, the trimmer can have a scraper 20 which extends substantially the full width of the trimmer so that the trimmer works the ground surface to substantially the entire width thereof. Also the trimmer can be towed behind a vehicle along public roads without substantial lateral protections. Also the wheels 31 need not leave any significant imprint in the ground by travelling along paths which are beyond the working width of the trimmer including the scraper 20 and the trailing roller 35.

[0032] The mounting means comprising the wheel system 16 and frame 12 also includes a ram 39 which is operative between the wheel system 16 and a portion of the frame to enable selective height adjustment of the bin 14 and associated scraper 20. In the illustrated embodiment, the ram 39 operates between a portion of the frame, particularly the rearward frame 18 adjacent the rear 23 of the bin 14 and the wheel frame 30. By extending the hydraulic ram 39, the wheel frame 30 and the hence the wheels 31 are moved downwardly relative to the frame 12 thereby elevating the bin including the scraper 20. When the maximum extension of the ram 39 is used, the bin 14 and particularly the scraper 20 can be elevated sufficiently above the ground surface to enable clear travel of the trimmer, e.g. for towing on public roads between sites where the trimmer is to be used. For such road travel, the roller 35 would be raised to the position shown in the drawing where it can be releasably locked. Of course, the trimmer can also be loaded onto a trailer or back of a flatbed truck for transport between sites.

[0033] The frame 12 has a forwardly extending portion 15 in the form of a bar having the towing connection or hitch 13 provided at its front end for releasably coupling the trimmer to a vehicle and by which the front of the trimmer is supported at a known height above the ground. The front portion of the frame 12 also includes a frame structure 50 providing mountings for the mechanism to selectively open and close the front opening closure 27. The structure 50 illustrated includes a front door ram 59 which is operable between the lower frame member 57 and a link assembly 51 which is coupled to the front door 27 so as to selectively close and open the front opening 22. The link assembly 51 includes two link members 52, 53 pivotally coupled together at 54. Link 53 is pivotally coupled at 55 to the front closure 27 and link 52 is pivotally coupled at point 57 to the elevated frame member 58.

[0034] A laser receiver 60 is mounted to the trimmer on support post 61 to receive signals relating to the local ground level so as to thereby enable automatic height adjustment of the scraper 20 by operation of the ram 39 and/or automatic control of the material holding control comprising front opening closure 27 (controlled by ram 59) and material pusher 43 (controlled by ram 42). Such laser levelling control systems are generally known in the relevant field.

[0035] In the illustrated trimmer, ground engaging skis 65 are provided on opposite sides of the trimmer at the front lower corners of the side walls of the bin 14. The skis 65 have coextensive lower planar surfaces which skid along the ground surface so that the skis help stabilize the travel of the trimmer along the ground and protect the front lower corners of the bin 14.

[0036] By the preferred sizing and the configuration, the levelling trimmer of the invention can be particularly manoeuvrable such that it can be used on domestic sized blocks of land or other confined spaces to achieve a manoeuvrable and adaptable levelling apparatus.

[0037] In one preferred form the trimmer has a width of 1.7 meters with the roller extending across this entire width and the bin may be fractionally narrower. The trimmer can have a length of about 2.4 meters providing a footprint of about 4.1 square meters. The trimmer can weigh about 800 kilograms. This provides a weight of less than 200 kilograms per square meter. This allows the trimmer to used on friable or unstable surfaces. It can also enable trimming without leaving significant physical imprints in the surface. With its preferred size and weight, the trimmer can be used with a 35 to 45 horsepower tractor that itself weighs about 1200 kilograms and has a length of about 3.6 meters and width of about 1.7 meters. Therefore the combination of tractor and trimmer can be transported on the back of a 20 foot truck or trailer and thereby alleviating transport difficulties encountered with larger machinery.

[0038] In use, if the ground surface level is lower than required, the pusher 43 will swing forwards in the bin 14 to force material out the front 22. The extent of opening of the front door 27 will control or choke the expulsion of the material to provide a smoothing of the material. If the ground surface level is above the required level, the height of the scraper 20 will be adjusted and the pusher 43 will move rearwardly to allow room within the bin to receive cut-away material and the front door 27 will be open to the required degree to allow material to enter the bin and, if desired, a percentage of material can be choked to provide a smoothing of the ground that is being levelled.

[0039] It should be evident from the description hereinabove that the present invention can provide an improved laser guided levelling trimmer that has significant advantages.

[0040] It is to be understood that various alterations, modifications and/or additions may be made to the features of the possible and preferred embodiment(s) of the invention as herein described and are incorporated herein without departing from the scope of the invention as defined in the claims. 

What I claim is:
 1. A ground levelling trimmer including: (a) a bin which includes a front opening and an associated scraper, which, in use, is able to scrape the ground surface being trimmed when the ground levelling trimmer is moved in a forward direction such that material removed by the scraper from the ground surface is collected through the front opening into the bin; (b) a mounting means having a wheel system including at least one ground engaging wheel and a frame by which the bin is mounted, the frame being mounted by the wheel system so as to allow selective elevational adjustment of the frame and of the bin mounted thereby relative to the wheel system so as to thereby enable selective adjustment of the height of the scraper relative to the ground surface; and (c) a material holding control associated with the bin for selectively controlling at least one of the collection into the bin through the front opening of material scraped from the ground surface and the discharge from the bin through the front opening of material within the bin.
 2. A trimmer in accordance with claim 1 wherein the material holding control is operative to selectively control both the collection into the bin through the front opening of material scraped from the ground surface and the discharge from the bin through the front opening of material within the bin.
 3. A trimmer in accordance with claim 1 wherein the material holding control includes a selectively operable closure associated with the front opening of the bin, the closure being selectively movable between a closed position in which it substantially closes the front opening against collection of material scraped from the ground through the front opening into the bin and a range of open positions which provide differing proportions of the area of the front opening to be available for passage of material scraped from the ground surface through the front opening and into the bin.
 4. A trimmer in accordance with claim 1 wherein the material holding control includes a material pusher located within the bin and which is selectively operable to push material within the bin forwardly so as to discharge material through the front opening of the bin.
 5. A trimmer in accordance with claim 4, wherein the material pusher is mounted in a rear of the bin, and is selectively controllable to swing forwards within the bin so as to push material in the bin forwardly towards the front opening.
 6. A trimmer in accordance with claim 5, wherein the material pusher is pivotally mounted at an internal upper portion of the bin so as to be movable in an arc to push material held in the bin towards the front opening.
 7. A trimmer in accordance with claim 6, in which the material pusher in vertical section has two planar parts angled obtusely internally of the bin so that the pusher is movable forwardly from a rear retracted position which minimally encroaches on the volume within the bin and so that the bottom edge transcribes the arc when moving forwardly through the bin.
 8. A trimmer in accordance with claim 7, wherein the internal bottom of the bin is arcuate in side view so that the bottom edge of the pusher follows this arcuate shape closely so as to allow effective movement of the majority of material in the bin by the pivotal forward movement of the pusher.
 9. A trimmer in accordance with claim 4, including a rearward extending frame mounted externally of the rear of the bin.
 10. A trimmer in accordance with claim 9, wherein a hydraulic ram is connected between the external rearward frame and the pusher to provide the required movement of the pusher within the bin.
 11. A trimmer in accordance with claim 10, wherein the ram extends into the bin in order to move the pusher and material in the bin towards the forward facing opening.
 12. A trimmer in accordance with claim 1, in which the bin has a shaped bottom having a front edge at which the scraper is located.
 13. A trimmer in accordance with claim 12, in which the scraper has a leading cutting edge defined by a leading face angled at about 45 degrees to a lower external bottom face which engages the ground surface so that an effective scraping or trimming occurs.
 14. A trimmer in accordance with claim 1, wherein a transverse roller is provided behind the said at least one ground engaging wheel for rolling along and thereby compressing the ground that has been scraped and levelled by the trimmer and for providing lateral stabilizing of the trimmer during use.
 15. A trimmer in accordance with claim 14, wherein the roller can be selectively moved from a ground engaging position to an elevated non-ground engaging position.
 16. A trimmer in accordance with claim 1 in which the wheel system includes two spaced ground engaging wheels, which are within the lateral dimensions of the bin.
 17. A trimmer in accordance with claim 1 wherein the mounting means includes a ram operative between the wheel system and a portion of the frame to enable selective height adjustment of the bin and associated scraper.
 18. A trimmer in accordance with claim 3, wherein said selectively operable closure comprises a front door which has a generally planar face which lies in the general plane of front opening and is selectively movable generally in that plane towards and away from the scraper to close and open the front opening.
 19. A trimmer in accordance with claim 18 wherein said front door is mounted for pivoting movement about a pivot axis located inwardly of the bin behind the front opening.
 20. A trimmer in accordance with claim 18 wherein a front door ram is operable between the frame of the trimmer and a link assembly coupled to the front door so as to selectively close and open the front opening.
 21. A trimmer in accordance with claim 1 wherein the mounting means including the wheel system and frame do not extend laterally beyond the sides of the bin.
 22. A trimmer in accordance with claim 1 wherein the scraper extends the entire width of the bin.
 23. A trimmer in accordance with claim 1, wherein a laser receiver is mounted to the trimmer to receive signals relating to the local ground level so as to thereby enable at least one of automatic height adjustment of the scraper and automatic control of the material holding control.
 24. A trimmer in accordance with claim 1, wherein ground engaging skis are provided on opposing sides of the trimmer, and having substantially co-extensive lower planar surfaces, such that the skis help stabilize the travel of the trimmer along the ground and protect the front lower corners of the bin.
 25. A trimmer in accordance with claim 1 wherein the trimmer is towable behind a vehicle in use, the frame having a forwardly extending portion providing a coupling hitch for releasably coupling the trimmer to the vehicle and by which the front of the trimmer is supported above the ground. 